You wanna be careful deleting things in the event and project folders. Before you do something manually, use the "Delete Render Files" in the File menu.

Regarding the titling performance, can you tell me more about your project? Length? What kid of media? Are you using compound or synchronized clips to edit? Do you have a lot of events loaded? Sounds like something is up in that regard.

For a quick fix without other troubleshooting, see if you type your text in TextEdit or other app and then paste it into the inspector text area (not the viewer). That should at least get you by until you can find what is up with your timeline.